The Bombkapsel 90 or BK90

Hello,

As I saw the great post made by renhanxue about the Rb 04E https://forums.eagle.ru/showthread.php?t=178005

I though we should have one for the great BK90, one of the most or the most advanced weapon we will have in DCS.

I don´t know much about the weapon but I found this video that seems to show how it will behave.

I hope the DEV team or somebody else can add more info about this thing.

:thumbup:

Well, well.

Best in depth description: https://drive.google.com/file/d/0B8bCDRcq9BVeUGxlNW5CaFhFQ2c/view

One of the 90s edits of the Viggen Manuals also has a very short section about it.

It is INS/radar altimeter guided, mostly low alt optimized. Due to the radar altimeter it is not recommended to launch over 500m AGL. Typical launch altitude would be 100m AGL, which gives you 7km range at mach 0.9. Up to 25degrees off boresight iirc, so you do not have to directly fly into the target.

There are two types of submunitions, MJ1 and MJ2.

MJ1 is anti personel style, 3 bomblets per tube, effective range 100m.

MJ2 is quite a unique submunition to my knowledge. Its an cylinder whichs wall are covered with indentations, which leads to it firing 110 EFPs with roughly the balistic characteristics of an 2a42 AP projectile, in a circular pattern, its also rated at 100m effective range. It will make short work of anything with the armor levels of an APC/SAM and probably also most IFVs. Each tube carries one MJ2.

Both submunition types are parachute retarded and will airburst or if that fails detonate on impact.

Submunitions can be mixed, the ejection timings are variable.

I at first had fears about the numbers of EFP spawned per BK90 and the DCS engine, but it isnt that bad. Even if you give them a lifetime of 0,25 seconds they already travel 500m, where they probably are already ineffective against anything but a flat btr80 side.

So you have at maximum, if you really set a low ejection timing like 0,1 second at 400kph dispenser speed that would be roughly 11 meters, 660 EFPs flying around. That is rouhly the same as 3 rockeye traditional cluster bombs. So it should be possible by the game engine.

You can have them either preprogrammed with coordinates before flight, enter the coordinates in flight, mark something on the a2g radar map or mark by overflight.

There is only one problem, even if you know the coordinates, the Viggen needs to have an quite accurate fix of its navigation system, since the BK90 INS is initialized with the Viggen position and then flies according to that estimate where it is. So if your Viggen nav has a drift of 500m, the bk90 is basing its targeting at an 500m offset as well. So you either have to mark it on the a2g radar map, then nobody cares because it is taking the relative range to an drifted assumption about the location. Or you have to fix the nav before releasing the BK90s.

I have two PDFs in the attachments which illustrate how MJ2 coverage will look depending on ejection spacing setting.

Yeah, siding with Rb-04 and RBS-15, this weapon will be VERY interesting in a SEAD or OCA mission context.

I tested some low level, flat terrain, ingress runs with the M2000, on runways defended by TORs and Tunguskas, and the air defenses are outrageous. This weapon can give some standoff.

Yeah, siding with Rb-04 and RBS-15, this weapon will be VERY interesting in a SEAD or OCA mission context.

 

I tested some low level, flat terrain, ingress runs with the M2000, on runways defended by TORs and Tunguskas, and the air defenses are outrageous. This weapon can give some standoff.

Rb 04/RBS 15 can't target land objects. The radar is designed for working at sea, so it would likely get confused by numerous contacts (look at the Rb 04 thread to see what I mean)

How this will be modeled I have no idea. My guess is the missile will either go for a random building or fly straight until it runs out of fuel/energy.

Rb 04/RBS 15 can't target land objects. The radar is designed for working at sea, so it would likely get confused by numerous contacts (look at the Rb 04 thread to see what I mean)

 

How this will be modeled I have no idea. My guess is the missile will either go for a random building or fly straight until it runs out of fuel/energy.

I know that rb04 and rbs15 are antiship missiles. I just put on bold theirs singularity at present DCS weapons availability. Good times with gameplay, ahead :) . Cheers.

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Hmmm but maybe we can use these anti-ship missiles in flat desert environment against airport, factory, or other large structures? :P

Hmmm but maybe we can use these anti-ship missiles in flat desert environment against airport, factory, or other large structures? :P

Very unlikely, more like NOPE.

RB05 and RB75T are there for a reason, ships in front of terrain.

Terrain in general just has so different reflective characteristics, that it would be pretty weird to work against anything but ships at sea.

Ah good point! The radar wave is probably not reflected the same way in desert and on water...

Hmmm but maybe we can use these anti-ship missiles in flat desert environment against airport, factory, or other large structures? :P

Actually, the RBS-15 MkIII is land attack capable so it might not be so far off :)

(currently only ship based AFAIK but LN could maybe maybe maybe give us a "what-if-scenario" missile version)

Actually, the RBS-15 MkIII is land attack capable so it might not be so far off :)

(currently only ship based AFAIK but LN could maybe maybe maybe give us a "what-if-scenario" missile version)

mkIII can only do that because of the GPS receiver it has. MKI and II dont have one. :)

And I really hope no RBS15 mk3, that would be pretty damn far off the real thing.

mkIII can only do that because of the GPS receiver it has. MKI and II dont have one. :)

 

And I really hope no RBS15 mk3, that would be pretty damn far off the real thing.

Yep, there's no need for the mk3. Just having the improved range of the rbs15 mk1 or mk2, comparing with rb04, will be very good.

And this thread as derailed :)

BK90, guys.

:)

so question to the Devs, will this have proper cluster weapon function? Unlike the CLuster munition on the Mirage? Evidently is a ED thing they need to import proper cluster munition profile for the Beluga to function correctly, will we be waiting for a properly functioning BK90 Also????

Anyone else notice?

Under the wings!? :smilewink:

Nice find, those sure do look like BK90.

Using this weapon at high altitude would be devastating.

A Viggen could fly at 30.000 feet and drop these things 20 miles from the target and then break away.

Using this weapon at high altitude would be devastating.

A Viggen could fly at 30.000 feet and drop these things 20 miles from the target and then break away.

Unfortunately you can't drop it from that altitude:

From the manual:

Release is possible between M 0.6 – M 0.9 at altitudes between 50 - 500 m AGL.

Farthest range you can hit a target from is probably about 9000m with optimal conditions (M 0.9, 500m altitude, no turning to target required)

Nice find, those sure do look like BK90.

Thanks, and I'm sure they are :)

Unfortunately you can't drop it from that altitude:

 

 

Farthest range you can hit a target from is probably about 9000m with optimal conditions (M 0.9, 500m altitude, no turning to target required)

A little lofting will probably help too, as long as it keeps the weapon within it's parameters.

A little lofting will probably help too, as long as it keeps the weapon within it's parameters.

Actually i dont think so, in the manual it is stated that the weapon will drop to approach altitude as soon as it is released, the approach altitude can apparently be set from the cockpit so i do not think that will make a difference.

Although i have no real knowledge on this so it is basically guesswork, maybe someone that really knows can comment?

Im pretty sure that's not the BK90, I think it is the pylon or "rack" that holds the small bombs, seen in the 11th picture from left to right https://forums.eagle.ru/showthread.php?t=177953

Im pretty sure that's not the BK90, I think it is the pylon or "rack" that holds the small bombs, seen in the 11th picture from left to right https://forums.eagle.ru/showthread.php?t=177953

You're probably right! Good catch!

Im pretty sure that's not the BK90, I think it is the pylon or "rack" that holds the small bombs, seen in the 11th picture from left to right https://forums.eagle.ru/showthread.php?t=177953

Those are 100% BK90s. They do looks similar to the bomb racks, but The BK90 have a ridge going down top of it.

The Bk90 also have a more rounded nose than the bomb racks.

Here's a model I made of it.

Sorry my bad! Tought they looked to narrow and to grey in the screenshot with the Tomcat compared to the first image in this topic.

No worries.

They aren't very wide actually, they are only 0.63m wide (1m with the wings).

There seems to be two different versions of the Bk90, a white one and a green one. Not sure if there is any difference between them other than the color.

A guess is that the green one was used on the Viggen, while the white one was used on Gripen. Just to match the color of the aircraft, but that might be wrong.

A little lofting will probably help too, as long as it keeps the weapon within it's parameters.

Regardless of how the guidance system works, the requirement to stay within 500 meters of the deck pretty much excludes any meaningful range boost by lofting. But the thing that's getting overlooked here is that it doesn't need it. 9 km of standoff range flying NOE at high speed is plenty.

Can't wait to try it out myself. And good idea to start the thread, as interesting as the ASM is the BK90 is what I foresee being my go-to in the Viggen as I'm sure it will be for many people. Was always interested to learn more about it.